Disc brake rotors having replaceable wear surfaces are well known to those skilled in the art. For example, U.S. Pat. No. 3,698,519 teaches a plurality of brake segments connected together to form a rotor braking surface. Each segment has at least two ears in each radially outward corner. A clip connects one ear from one segment to an ear of an adjacent segment. Two rivets are located in each clip to connect adjacent ears of adjacent segments together.
U.S. Pat. No. 3,726,374 provides for a rotor comprised of a plurality of concentric rings with a gap located between each ring. Adjacent facing members having overlapping ears are fixed to the rings with rivets. Friction lining materials are fixed to the facing members with rivets.
U.S. Pat. No. 3,757,907 teaches a central carbon base core and carbon based wear pads on both sides of the core. Key slot segments secure the wear pads to the core by locating rivets through holes in the slots and the core and pads.
U.S. Pat. No. 3,904,000 depicts and describes a brake disc comprised of a plurality of brake segments. The segments are joined together by clips on the outer periphery of the segments. Rivets are used to secure the clips to the segments.
U.S. Pat. No. 4,747,473 provides for a brake disc comprised of a plurality of segments each connected together at their outer periphery by a torque link. Each torque link has an eyelet on each of its ends. Each of the segments has a raised portion with an eyelet therethrough. The torque link spans the gap between adjacent segments and the eyelets on the torque link are aligned with the eyelets in the segments. A rivet is located through each eyelet to secure the segments together as a ring.
U.S. Pat. No. 5,439,077 teaches a brake ring divided into two segments. A pair of ring grooves are formed in the brake ring adjacent the gap between the two segments. A ring body is inserted into each ring groove to join the two segments. The ring segments are secured to the disk by screws or clamping sleeves.
Lastly, U.S. Pat. No. 6,557,672 provides for a friction ring divided into at least two ring segments. The ring segments are attached to the wheel disc by fastening devices, such as bolts. The ring segments are hinged together in an interlocking relationship.
The prior art also discloses locking mechanisms for the replaceable wear surfaces. For example, U.S. Pat. No. 2,541,979 describes and depicts a brake shoe with a plurality of clamping strips located on its outside surface. Flanges on the clamping strips act as guides for friction blocks. Each block has a pair of grooves for engaging and receiving the flanges on the clamping strips. A bolt is inserted through a hole in the brake shoe and into the clamping strips. The head of the bolt engages with the flanges on the clamping strip to spread them into gripping engagement with the friction blocks. The position of the bolts are secured with a nut bearing against the brake shoe.
U.S. Pat. No. 3,746,139 teaches a rigid disc member with opposing faces on which brake material segments are attached. The segments are located in spaced-apart positions about the circumference of the disc member. Grooves in the sides of adjacent segments each accommodate one half of a clamping member. The clamping member is then riveted to the disc member, thus securing the clamping member, and the segments under the clamping member, to the disc member.
U.S. Pat. No. 3,917,043 provides for a disc member having friction lining segments attached thereto. U-shaped brackets extend around the inner peripheral edges of the friction lining segments and the disc member. Rivets are used to secure the brackets to the disc member. Slots are located in the outer peripheral edge of the disc member. The slots extend radially into the body of the disc member. Sliding blocks are located in the slots. Edges of the segments have recesses for engagement with edges on the sliding blocks to hold the blocks in place. The blocks and brackets secure the segments in place. An alternative embodiment disclosed in the patent locates the U-shaped brackets on the outer peripheral edge and inserts the blocks through slots opening on the inner peripheral edge.
U.S. Pat. No. 4,350,231 discusses and discloses brake pads with mounting tangs formed of the same material as the pads. A core member is provided with slots to receive the tabs. A tubular clip is fitted over the ends of the tabs to draw the pads together and secure them in place on the core member.
U.S. Pat. No. 4,613,021 teaches a disc comprising a core consisting of six or eight radial arms spaced equally apart around a hub. The arms have a rectangular cross section and end in a double hook shaped flange. The hooks of the flange point toward the center of the hub creating a oblique bearing surface on either side of the core. Friction pads are attached to both sides of the disc. The pads are secured to the disc by being hooked and held both radially and axially by their outer edges. Spring-like rings, attached to the hub, are brought to bear against a tapered bearing surface of each pad.
U.S. Pat. No. 4,763,762 provides for a pad element attached to a disc element by a rivet. A T-shaped clip is arranged to overlap a side and upper edge surface of the pad element. The pad element has recesses along the side and upper edges to accommodate the thickness of the T-shaped clip. The T-shaped clip has spaced apart rivet openings to receive rivet-like heads. The riveted T-shaped clip and the rivet located in the pad element holds the pad element to the disc element.
U.S. Pat. No. 6,439,353 depicts and describes a support ring having a plurality of radially extending support arms. A brake segment is located in the gap between each support arm. The outwardly protruding free end of each one of the support arms is equipped with a locking member. A bolt, or screw, is located in each of the locking members to secure it in place. The support ring and arms may be constructed of a dissimilar material from the brake segment. A damaged, or worn out, brake segment may be removed and replaced with a new brake segment by loosening the bolt and rotating the locking members out of engagement with the segment.
The prior art described above is disadvantageous since most require the brake caliper, seals and/or bearings to be removed when the wear surfaces need to be replaced. Most of the prior art also requires the entire rotor to be removed from the hub to replace worn or damages wear surfaces. Additionally, most of the rotors described above require that the core, or wheel disc, that supports the wear surfaces must be the same material as the wear surface material. If exotic materials are used for both the wear surface and the wheel disc, the prior art designs greatly increase the cost of the product.
In light of the disadvantages of the prior art, it would be desirable to have a rotor assembly that allows for a variety of wear surface materials to be used with a low cost core. It would also be desirable to have a rotor assembly that did not require the assembly to be removed from the hub, that did not require the caliper to be removed, and that minimizes the need to disturb other wheel end components, such as bearing and seals, to change the wear surfaces. It would also be desirable to replace a single damaged, or worn, wear surface rather than having to replace all the wear surfaces when only one needs to be replaced.